New Machine Build- 24"X36" All Steal Gantry Mill, 500 oz Chopper driven!

[EvanZ]

Ok where to start. I finally got everything in for this beast and have started my mill. It is more of a mill then it is a router but has a great range of speeds. It will be good for steal on the slow end all the way up to 27,500 on the upper end. It has home aid everything I built it from complete scratch. The the machine is made of steal and has been straightened at the machine shops here at school. When everything is fitted it will be torn down and sent back to the shops to be surface ground to perfection. the screws still have to be turned but I have .750" acme screws by 6 threads per inch. The bearings are .500" ID cast flange style. Motors are from Hubbard and are 500 in oz 4 wire.

The Control box is done and the circuit boards, the transformer and stepper motors are all water cooled to ambient temps. The power supply is an Antek dual 40V tap at 20 amps run in parallel to two a bridge rectifier and then out the DC side to two 45 volt 36,000 Micro Farad caps run in series. (As I am putting out a bit more than 45 volts, I was reminded what happens to caps when they are over powered, a nice 6 foot high geyser of boiling oil! YAY! lol) from there the voltage reads about 55 Volts DC run into the Chopper drivers and out to the three axis. I have pre wired the box for 5 axis as this may just be a future need. The power supply has the capability of 55 Volts 20 Amps very nice stable power. I have build over systems into the power supply to regulate it even more but we will keep all that in my little bag of tricks for now. . The other 2 sets of 12 volt taps are run in parallel to a second rectifier ad then through its own 45 volt 36,000MFD cap. I get a very solid 16.7 volts DV outta this and that is then run through a variable regulation setup so I can use that power just about what ever voltage I need it from 0 to 18 volts DV. However I have it set at 12 volts for the circuit power for other boards I have in the controller. Next we move on to the breakout boards which are a simple combo of two C10 Boards from CNC4PC. Top board is for outputs from the computer such as step/direction ect. The second is for inputs the whole machine will have encoders at some point and this is set up for 5 axis inputs. The E stop is run to the top board. There is a modified Voltek power supply given the box a set of 5 volt DV outputs and one tap for a low amp 12 Volt DV output to run the display panels and meters on the control boxes main control panel. One of the five volt supplies from the Voltek runs the system voltage four the breakouts. There will also be of course a remote wand setup.

There are six channels of solid state 110-220VAC output in the box, two of which are VFD. Yes my box has VFD built it. . Two of these channels will allow Mach three to run the toolhead Coolant/Lube flood pump, and the motor/driver/board/spindle coolant pump. All of the pumps are in a closed loop E-Stop system. If the coolant flow stops for either system or the temp goes above given operating parameters, it will trigger an E-Stop input for Mach 3. They also all have manual override switches on the main control panel. ( Or will one I get the nerve up to cut all the holes in it with that damn Dremel NOISY)

What am I forgetting here......The spindle is 2.5 HP water cooled, umm The damn thing is HEAVY, umm motors are connected with lovejoys.....I donno I'm sure I will think of more and amend this soon.

I have included a few pics to give you some visual ques here. There should be a few on the lab, my tinkering with mach 3, and some good shots of the controller. These pics are a bit behind current completion as there has been more work done but I will get those on as soon as I can.

Also here's a link to a video I made if it running.
http://www.zerbymedia.com/ezcrib/cnc...t/SSPX0510.3g2

Thanks for all the help over the last year, I hope you enjoy my need to go nuts with projects.

Evan

[EvanZ]

Ok how about this. Anybody have any suggestions for swarf covers?

Thanks Evan

[MrWild]

Your control panel is artwork. Nice job. Beauty of a set up. I'm sure it will rip through wood like a rabid beaver. You may be able to cut aluminum, but steel is a different animal and your gantry isn't ridgid enough. The culprit is two angle iron arms cocking the works. An angle iron on either end just isn't ridgid enough. Harmonics will kill you with chatter. Don't let that discourage a very nice build though. It is pretty sweet.

[CarveOne]

I agree with MrWild's angle iron comment.

Try it as it is initially, but if it becomes a problem, add a piece of the same plate that you used at the lower end of the angle irons to extend the plate upwards to the top of the gantry. Weld it to the lower plate and bolt or tack weld it to the angle iron every few inches higher up. (Or make new one piece plates.) You could taper the extended plates if you wish to.

Another option is to replace the angle iron upright with a piece of the same box tube that you used on the base. You could even use the upright plate in addition to the box tube if you choose to bolt the upright plate in my first suggestion.

CarveOne

[EvanZ]

See they have been bugging me too. As all projects go this one evolved durring it's build. When I started out I was stuck on a farm in Southwestern Kansas, so what I had access too was steal. It was to be a light duty machine. As it got further along it became clear how efing solid the machine was becoming. Of course there is a weak link in every chain, and mine happends to be the links between the super solid base and the super solid uptter end, yeah those damn uprights. I'm thinking we will put this machine into service and either build a new set of uprights for the gantry, or just chalk it up as learning and move on to the next build.

If I did upgrade the uprights I havn't decided if I would use like C Channel or square tube, or square tube with flat plate welded to it. I just donno. Calling all brains....

Evan

[tiggeraaron]

Nice work Evan!! You can always tell how much a person cares about a project by looking into how it is wired. Beautiful control system. Nothing wrong with using steel for machine builds. Weight and rigidity is your friend.
Later,
Aaron

[CarveOne]

Ok, one more idea to consider to strengthen the uprights.

Make a second pair of angle irons that fit against the existing uprights and tack weld them together every few inches. Almost as strong as box tubes and easier to implement.

One more mechanical note:

If your z axis motor seems to be sluggish when moving upwards but not when moving downwards it may be the combined weight of the steel slider assembly coupled with the weight of the router (assuming that you will be using a full size router). I don't know anything about the motor torque and lead screw you will use yet so I'm just guessing at this point. Lifting a lot of weight against gravity can be an issue in steel designs. It can also cause excessive wear on the lead screw and lead nut.

I don't see anything else to point out at this point except that my second machine will be steel construction as well and I have already researched some of the things to look out for. These suggestions seem to be the major issues to consider.

Your wiring does look very neat and orderly as others have pointed out. I noticed that you twisted the related wires. What this does is help to minimize cross-coupling of unlike signals in a bundle. It also helps to twist some of them clockwise and some of them counterclockwise in the bundle. The tighter the twist the more capacitance the pair of wires will have per foot. This coupling capacitance can be a signal distortion problem for higher speed digital signals.

Best of luck with the rest of your build!

CarveOne

[EvanZ]

You mean inductance correct? That was why I twisted my signal wires. I O-Scoped everything and ran an inductance test on all the harneses. Cancelation was very good with the wires wrapped at 3 twists per inch for the low voltage side and 1.7 twists per inch on the high voltage side. Much more then that and there was a big spike in the resistance in the winds. Gotta love good test equipment. As far as the Z axis somewhere down in the first post I listed the screw at .750" X6 Acme Lead Screw. The motors are all water cooled 500in oz motors run at around doubleish power. 55Volts at 20 Amps. I'm not sure what my total Z weight will be but I do forsee any lift issues. Do you? Maybe I am incorrect. The Z is not direct drive like the X and Y are. Z will be belt drive running two 1.892" Pullys at 30 teeth each. It will be running one to one and If I remember correctly this is about the smallest pully my supplier (Hubbard) said there was. If I could get something smaller I guess I could drop the ratio for Z but I donno if I need to.

Thoughts folks?

Evan

[EvanZ]

Oh fyi. Motor shafts are .375" and Screw shafts are .500"

I don't think that maters but just spewing more info. lol

[CarveOne]

Originally Posted by EvanZ You mean inductance correct? That was why I twisted my signal wires. I O-Scoped everything and ran an inductance test on all the harneses. Cancelation was very good with the wires wrapped at 3 twists per inch for the low voltage side and 1.7 twists per inch on the high voltage side. Much more then that and there was a big spike in the resistance in the winds. Gotta love good test equipment. > snip< Evan

The answer is yes. It increases both inductance and capacitance as compared to loosely bound parallel wires.

Yes, good test equipment is nice to have. All I ever had belonged to my employer though. It allowed me to design and test 2.5GHz signal traces in 20 layer boards. The newer transmission line driver chips that came out before I retired from it let 5GHz signals pass over those same traces.

CarveOne

[EvanZ]

Very cool stuff, I would kill to have that kinda stuff in my lab. I have it at school, but I dropped a TON of money to build this lab as it is. At school I'm doing alot with integrated control with rat brain neurons in conjunction with Dr. Warwick in the UK. That guy is using CRAZY layerd boards! But alas I don't have the hundred million dollar budget, sigh... Just think of what CNCZone people could do with 100Million dropped on us.

Evan

[CarveOne]

For 100Mil, early retirement comes to mind...

Meeting telecom industry specifications is not very easy. I worked as a manufacturing test technician, development engineering lab technician, and then a non-degree backpanel design engineer for around 40 years. Many of my board layouts needed to meet tough lightning surge and high speed signal specs in various parts of the same board and still meet EMC compliance specs.

I don't do that anymore, but I still enjoy my work and home projects nonetheless. It's amazing how much I don't miss it (mostly the high pressure schedules) anymore.

CarveOne